Study On The ABR Start-up And The Experiment Of The Anaerobic Sludge Granulation Process

The Anaerobic Baffled Reactor (ABR) is a new high-efficient anaerobic reactor. The wastewater can intimately contact with a large amount of activated sludge when it passes through the reactor. At the same time, its unique structure and flow characteristics can make good condition for the formation of anaerobic granular sludge.The reactor's start-up and anaerobic granular sludge cultivating method were studied based on a series of testing using starch and glucose wastewater. After start-up experiments, the ABR was used to treat slaughterhouse wastewater. In this work, the most suitable operating condition of ABR was studied. The result could be summarized as follows:1.When the reactor was started using low loading start-up , VLR controlled at 0.59～11.05kgCOD/m3·d, there are some granular sludge appeared after running 18 days. The figure and size of granular sludge in each compartment revealed different characteristics due to the changing of OLRs and shear force between gas and liquid in each compartment. The COD removal efficiency was higher than 90% and steady when the reactor's start-up finished.2.When the anaerobic granular sludge appeared in the reactor, the VLR was 1.29kgCOD/(m3·d),COD removal efficiency was 83%,hydraulic surface loading was 0.078m3/m2.h and an HRT was 30h. At the beginning of the experiment, activated carbon and PAM was added into the first and the third compartments, after start-up experiments, the granular sludge grain size and contents in the first and the third compartments were higher than the second and the fourth compartments'. The VSS/SS in each compartment exceeded 70%, granular sludge has high biology activity.3.The VLR had remarkable influence on COD removal efficiency,VFA,pH and ALK. When VLR was 5.57kgCOD/(m3·d), COD removal efficiency and ALK were the minimum, VFA in the outflow exceeded 1000mg/L, reactor's efficiency decreased .The reactor recovered after adjusting VLR and ALK value. Compared with the third and fourth compartments, the first and second compartments were less sensitive to changing of VFA. When pH deviated from adapt range, the COD removal efficiency was decreased obviously, so pH value was kept in the range of 6.2 to 6.5 for the later stage of experiments. 4.The best reactor operated time is 21th~31th day and the experimental condition were HRT: 30~26.7h, VLR: 24.8~5.36kgCOD/(m3·d). During this period, sludge activity reached optimized condition, microbial grew exuberantly and the anaerobic granular sludge demanded a large mount of nutrition during this period. Under the suitable HRT and VLR condition, COD removal efficiency exceeded 98%.5.The ABR was used to treat slaughterhouse wastewater after the cultivation of anaerobic granular sludge, COD removal efficiency was over 60% when VLR changed between 0.46 and 6.62kgCOD/(m3·d).The best operate parameters are 15h HRT and VLR 4.8~5.2kgCOD/(m3·d), and the COD removal efficiencies could be more than 75%.